Chuck.



F. L. SMITH L T. B. WILLIAMS.

CHUCK.

APPLICATION FILED 1\.IAR.26,1913.k

1,989,727.. Patented Dec. 9, 1913.

ffgt. F54 54 5f 52 @,ef; zzyzzasi TTNTTEU STATES PATENT FFTQE FRANK Ii. SMITH, 0F CHICAGO, ILLINOIS, AND THOMAS B. WILLIAMS, 0F OMNG, MASSACHUSETTS, ASSIGNOBS TO LEAVITT MACHINE COMPANY, 0F ORANGE, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

CHUCK.

Specication of Letters Patent.

' Patented Dec. 9, T913.

invented new and useful Improvements in Chucks, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to provide an improved form of chuck especially adapted for grippin and holding threaded pieces such as pipe ttings, without injury to the threads. f

It consists of the features and elements described and shown in the drawings as indicated by the claims.

In the drawings :.-Fi ure 1 is a perspective view of a chuck ein odying this invention. Fig. 2 is a detail elevation of one of the 'aw members of the chuck shown in Fig. l. Fig. 3 is a detail section taken as indicated at line 3-3 on Fi 2. Fig. 4 is a detail section taken as in icated at line 4-4 on Fig. 2.

The chuck shown in the drawings comrises a body portion, A, preferably of c linrical form, in which there are sli ably mounted a plurality of jaw members, B, arranged for radial adjustment toward and from the axis of the body, A. Each of the jaw members, B, is somewhat similar in general appearance to the usual ste ped jaw ordinarily supplied in this form o chuck as used on lathes, milling machines and the like, but in addition to the rovision of stepped gripping surfaces for t e accommodation o various sizes of work, these jaw members having their gripping surfaces serrated; and the serratlons are made in the form of segmental portions of threads. The most general use o this type of chuck will be for holding threaded valve fittings, and for this purpose the threads of the several gripping surfaces will be-of various pitches corresponding to the usual threads on such fittings of such diameters as these several surfaces are designed to enga e, respectively. t may be understood t at the inwardly facing jaw surfaces, 1, are concavely formed for en aging externally threaded fittings, while t e outwardly facteriorly threaded pieces.

. feature need not be further described.

are convex to conform to in- By reason of the curvature of the gripping surfaeesihe w members are not reversi le in their ra ial slots as in common'types of lathe chucks and must, therefore, comprise complete series of both inwardly and outwardly facing jaws, this being accomplished b cutting away the material as indicated at, a, thus forming a secondar series of Asteps with threaded projections, 4, extending from them.

It will be understood that the radial adjustment and secureinent of the jaws and their guide ways in the body, A., may be accomplished in any familiar manner, and this ing jaws, B2,

We claim y 1. A chuck comprising a body portion and jaw members mounted radially therein for converging and diverging movement, said members aVing each a plurality of shoulders forming pipe-gripping` surfaces parallel with the axis toward which the jaw members converge, said shoulders being provided with serrations constituting se ments of screw threads formed about sai axis, the threads of said pipe-gripping surfaces being successively coarser and coarser as said surfaces are successively more and more remote from the axis, and corresponding substantially to standard threads of the ipe sizes, adapted to be gripped by said surfdces respectively.

2. A chuck comprising, a bod portion and a pluralit of jaw members a justabl carried there y for movement toward an from a central axis, each of said jaw members having a plurality of projections extendin parallel to the aforesaid axis, the inner an outer faces of such projections with respect to said axis being serrated, and such serrations constituting segmental portions of screw threads.

3. A chuck comprisin ,a body portion and a pluralit of jaw mem ers adjustably carried there y for movement toward and from a central axis, each of said jaw members having a series of steps and having a projection extending from each step parallel with the aforesaid axis, the inner and outer faces of such projections with respect to said axis being serrated, and such serrations constituting segmental portions of screw threads.

d. A chuck comprising, abody portion and a piuralit of jaw members adjustablv carried there y for movement toward and from a central axis, each of said jaw members havfing a projection extending parallel to the 5 aforesaid axis, the inner face of said projecl' tion with respect to the axis being concave and the outer or opposite face being convex, and said inner and outer faces having serrations constituting segmental portions of female and male threads, respectively.

5. A chuck comprising, a bod portion and a pluralit of jaw members a justably carried there y for movement toward and from a 'central axis, cach of said jaw members having a plurality of projections extending parallel to the aforesaid axis, the gripping surfaces of each projection having serrations constituting segments of a screw thread,fand thethreads of the several projections being of different pltehes corresponding to various sizes of standard threads.

Witnesses for Smith:

EDNA M. MACINTOSH, Ro'r. N. BURTON.

Witnesses for Williams:

GEORGE W. ANDREWS, B. H. WALKER. 

